Explanation:

- Kaveri (Option 1): This river flows mainly through Tamil Nadu and Karnataka. Its total length is about 800 km, making it one of the shorter major rivers in India.

- Godavari (Option 2): Known as Dakshina Ganga, the Godavari is the second-longest river in India, stretching about 1,465 km.

- Brahmaputra (Option 3): The Brahmaputra is a mighty river, but its length within India is about 916 km. Its total length including Tibet and Bangladesh is greater, but only its Indian stretch counts here.

- Ganga (Option 4): The Ganga is the longest river within India, flowing about 2,525 km from the Himalayas to the Bay of Bengal.

Correct answer: Option 4 - Ganga